Fabric and articles having fire-resistance, cut-resistance, and elastic recovery and processes for making same

ABSTRACT

A flame-resistant cut-resistant fabric, and a glove or other article comprising the fabric, the fabric comprising:
         (a) at least one first yarn comprising at least 50 weight percent heat-resistant polymeric fiber, wherein at least 30 weight percent of the polymeric fiber present in the at least one first yarn is cut-resistant heat-resistant polymeric fiber having a cut resistance of 500 grams force or higher per ASTM F2992-15; and   (b) at least one second yarn having a sheath/core construction with a sheath of halogenated self-extinguishing staple fibers and a core comprising at least one continuous elastomeric filament,   wherein 60 to 95 weight percent of the at least one second yarn is halogenated self-extinguishing fiber, and the halogenated self-extinguishing fiber is in contact with the at least one continuous elastomeric filament, the second yarn being free or substantially free of inorganic fibers;   the fabric having a maximum after-flame time of two seconds or less and weight loss of 5 weight percent of less when tested per NFPA-2112-2018.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to yarns and fabrics suitable for use in articlesof protective clothing that have fire-resistant and form-fittingproperties and also have cut resistant properties.

Description of Related Art

Ply-twisted yarns and fabric having cut-resistance and elastic recovery,processes for making same, and their used in articles of protectiveclothing is disclosed in U.S. Pat. No. 6,952,915.

Yarns comprising modacrylic fiber, p-aramid fiber, and m-aramid fiberthat are useful for the production of fabrics which possess arc andflame protective properties are disclosed, for example, in U.S. Pat.Nos. 7,065,950 and 7,348,059. These yarns may further comprise, as anoptional component, 2 to 15 weight percent of an abrasion-resistantfiber such as a nylon and/or 1 to 5 weight percent of an antistaticcomponent.

Yarns and fabrics having a combination of fire resistance and elasticrecovery properties are described, for example, in U.S. Pat. Nos.5,069,957; 5,527,597; and 5,694,981. These existing solutions utilizeyarns made by covering elastic core yarns with a substantial protectivefiber outer covering made from a fire-resistant fiber. In other words,these references describe protecting the elastic core by structurallyshielding the elastic core from flame by use of another fiber that is inthe same yarn.

As used herein, the terms “structural shielding” and “structural shield”mean the cover fibers simply char and remain in place in a yarn coveringany elastic filaments in the core when exposed to a flame and thereforeprovide a structural barrier between a flame and the elastic core. Astaught in these patents, these yarns are provided with a substantialprotective fiber outer covering made from a fire-resistant fiber thatphysically protects the elastic core yarns from degradation or melting,when exposed to extreme temperatures and fire.

Unfortunately, in many instances, the fibers that provide an adequatestructural shielding outer fiber covering also tend to be stifferfibers, and therefore fabrics made with such yarns can be lesscomfortable than desired. This ultimately translates to protectiveapparel that can be less comfortable than desired, and it is well knownthat workers tend to not wear their protective gear if it is notadequately comfortable, putting themselves at risk.

Additionally, any solution for protecting the elastic core should meetcurrent protective apparel standards. Specifically, the recent NFPA2112-2018 “Standard on Flame-Resistant Clothing for Protection ofIndustrial Personnel Against Short-Duration Thermal Exposures from Fire”provides specifications for the minimum design, performance, testing,and certification requirements and test methods for flame-resistantgarments, shrouds, hoods, balaclavas, and gloves for use in areas atrisk from short-duration thermal exposure from fire. The Standardrequires the fabric used in the garments have an afterflame time of notmore than 2 seconds. The afterflame time is the time, in seconds, to thenearest 0.2 second, that the specimen continues to flame after theburner is removed from the flame.

The Standard has even more stringent requirements for flame-resistantgloves, in that the material consumed in the flame resistance testingshould not exceed 5.0 percent of the specimen's original weight. Inother words, after the specified 12 seconds of flame is applied to aspecimen per the procedure in the Standard, the fabric weight lossshould be 5.0 percent or less.

Therefore, what is needed is a yarn and/or fabric having a combinationof fire resistance and elastic recovery properties, along with cutresistance, that specifically incorporates elastic core yarns, thatmeets the NFPA 2112-2018 Standard; and that further utilizes fibers thathave a textile feel to potentially provide a more comfortable protectiveapparel article.

BRIEF SUMMARY OF THE INVENTION

This invention relates to a flame-resistant cut-resistant fabric, and aglove or other article comprising the fabric, the fabric comprising:

-   -   (a) at least one first yarn comprising at least 50 weight        percent heat-resistant polymeric fiber, based on the total        weight of the first yarn, wherein at least 30 weight percent of        the polymeric fiber present in the at least one first yarn is        cut-resistant heat-resistant polymeric fiber having a cut        resistance of 500 grams force or higher per ASTM F2992-15; and    -   (b) at least one second yarn having a sheath/core construction        with a sheath of halogenated self-extinguishing staple fibers        and a core comprising at least one continuous elastomeric        filament,    -   wherein 60 to 95 weight percent of the at least one second yarn        is halogenated self-extinguishing fiber, based on the total        weight of the second yarn, and the halogenated        self-extinguishing fiber is in contact with the at least one        continuous elastomeric filament, the second yarn being free or        substantially free of inorganic fibers;    -   wherein the fabric has a maximum after-flame time of two seconds        or less and weight loss of 5 weight percent of less when tested        per NFPA-2112-2018.

DETAILED DESCRIPTION OF THE INVENTION

This invention relates to yarns and fabrics, suitable for use inarticles of protective clothing, that have both fire-resistant andform-fitting properties, and additionally provide cut protection. Theunique combination is created by combining elastic materials,self-extinguishing fibers, and strong heat-resistant polymeric fibers ina manner to provide high fire resistance in a yarn or fabric along withlimited consumption of the fabric during burning.

Specifically, this invention relates to a flame-resistant cut-resistantfabric, comprising:

-   -   (a) at least one first yarn comprising at least 50 weight        percent heat-resistant polymeric fiber, based on the total        weight of the first yarn, wherein at least 30 weight percent of        the polymeric fiber present in the at least one first yarn is        cut-resistant heat-resistant polymeric fiber having a cut        resistance of 500 grams force or higher per ASTM F2992-15; and    -   (b) at least one second yarn having a sheath/core construction        with a sheath of halogenated self-extinguishing staple fibers        and a core comprising at least one continuous elastomeric        filament,    -   wherein 60 to 95 weight percent of the at least one second yarn        is halogenated self-extinguishing fiber, based on the total        weight of the second yarn, and the halogenated        self-extinguishing fiber is in contact with the at least one        continuous elastomeric filament, the second yarn being free or        substantially free of inorganic fibers;    -   wherein the fabric has a maximum after-flame time of two seconds        or less and weight loss of 5 weight percent of less when tested        per NFPA-2112-2018.

By “flame-resistant cut-resistant fabric”, it is meant a knitted orwoven fabric that is both “flame resistant” and “cut resistant”. By thedescriptor “flame resistant”, in regard to a fabric, it is meant thefabric has a char length equal to or less than 4 inches (100 mm) whentested per ASTM 6143-15. By “cut resistant fabric”, it is meant thefabric has at least a minimum level of cut resistance, and generally acut-resistant fabric has a cut resistance of at least 200 grams forceper ASTM F2992-15. In some preferred embodiments, the fiber and yarnsdescribed herein can provide a flame-resistant cut-resistant fabrichaving a cut resistance of at least 500 grams force per ASTM F2992-15.However, it is understood that in some other embodiments, other fibersor yarns that don't necessarily provide cut resistance but may provideother desirable qualities to the fabric may be incorporated into thefabric as long as the flame performance requirements describe herein tobe considered a “flame-resistant” fabric are met and the fabric retainsa minimum cut-resistance of at least 200 grams force per ASTM F2992-15.

Flame-resistant fabrics provide thermal protection from thermal events,while cut resistant fabrics provide mechanical protection from suchthings as knives and sharp edges. The fabric, in addition to being flameresistant, has an afterflame time of two seconds or less and weight lossof 5 weight percent of less when tested per NFPA-2112-2018.

In addition, it is often important or desirable for any articles, suchas protective gloves, that are made from such fabrics be comfortable andhave good fit and dexterity. By “good fit and dexterity” it is meant,for example, that gloves conform nicely to the shape of the hands of thewearer and one is able to pick up and manipulate small objects whilewearing the gloves. The flame-resistant cut-resistant fabrics asdescribed herein are both highly flame-resistant and cut-resistant,while also providing articles that are soft, flexible, and form fitting.Protective apparel made from such fabrics is very comfortable andeffective against multiple threats.

The flame-resistant cut-resistant fabric is made from at least a firstyarn that provides a heat-resistant polymeric fiber and at least asecond yarn that provides at least one continuous elastomeric filamentcovered by halogenated self-extinguishing fiber that is in contact withthe at least one continuous elastomeric filament. The at least firstyarn and the at least second yarn are then used to make the fabric.

In some embodiments, the at least first yarn and the at least secondyarn are twisted together to form a ply-twisted yarn. In someembodiments, the ply-twisted yarn consists of only one first yarn andonly one second yarn. In other embodiments, the ply-twisted yarnconsists of only one first yarn and a plurality of second yarns; and inother embodiments, the ply-twisted yarn consists of a plurality of firstyarns and only one second yarn. Likewise, in some embodiments theply-twisted yarn consists of a plurality of first yarns and a pluralityof second yarns. Finally, in some embodiments, the ply-twisted yarncomprises at least one first yarn and at least one second yarn; otheryarns made from any number of fibers can be included in ply-twisted yarnas long the final fabric meets the performance criteria discussedherein.

In some other embodiments the at least first yarn and the at leastsecond yarn are used in a co-knitted weft insertion structure. By “weftinsertion” it is meant a knit wherein the at least second yarn isinserted into a knitted structure comprising the at least first yarn,such as is done in making elastomeric cuffs in knit gloves.

In some other embodiments the at least first yarn and the at leastsecond yarn or can be used in a parallel relationship to each other inthe fabric. The word “parallel”, as used herein, means that theindividual yarns are generally present in the fabric next to each otherside-by-side and that the yarns are independent and separate from eachother, they are not plied or twisted together. In knit fabrics, thistype of parallel arrangement in the fabric is also known as one type ofco-knit fabric. In one co-knit manufacturing process, the co-knit isformed by knitting the two separate yarns two-ends-in, i.e., bothtogether, on a single knitting machine. This structure and processmaintains the two different yarns in close proximity in the fabric,maintaining their parallel relationship. The process can advantageouslyinclude the step of plaiting the two ends of yarn during knitting tolocate one of the ends predominantly at a first surface of a garment,and the other of the ends predominantly at a second surface of thegarment. This allows placing of the typically more comfortable endpredominantly on the inside of a garment and locating the otherpredominantly on the outside.

This invention also relates to a glove or other article comprising aflame-resistant cut-resistant fabric including all of the embodimentsdescribed herein, the flame-resistant cut-resistant fabric comprising:

(a) at least one first yarn comprising at least 50 weight percentheat-resistant polymeric fiber, based on the total weight of the firstyarn, wherein at least 30 weight percent of the polymeric fiber presentin the at least one first yarn is cut-resistant heat-resistant polymericfiber having a cut resistance of 500 grams force or higher per ASTMF2992-15; and

(b) at least one second yarn having a sheath/core construction with asheath of halogenated self-extinguishing staple fibers and a corecomprising at least one continuous elastomeric filament,

wherein 60 to 95 weight percent of the at least one second yarn ishalogenated self-extinguishing fiber, based on the total weight of thesecond yarn, and the halogenated self-extinguishing fiber is in contactwith the at least one continuous elastomeric filament, the second yarnbeing free or substantially free of inorganic fibers;

wherein the fabric has a maximum after-flame time of two seconds or lessand weight loss of 5 weight percent of less when tested perNFPA-2112-2018.

The at least one first yarn comprises at least 50 weight percentheat-resistant polymeric fiber, based on the total weight of the firstyarn, wherein at least 30 weight percent of the polymeric fiber presentin the at least one first yarn is cut-resistant heat-resistant polymericfiber having a cut resistance of 500 grams force or higher per ASTMF2992-15.

By “heat resistant polymeric fiber”, it is meant a fiber made from asynthetic organic polymer that retains 90 percent of its original fiberweight when heated in air to 500° C. at a rate of 20° C. per minute.Preferred heat resistant polymeric fibers have a yarn tenacity of atleast 3 grams per denier (2.7 grams per dtex). Heat resistant polymericfibers include para-aramid fibers, aramid copolymer fibers,polybenzazole fibers, polybenzimidazole fibers, polyimide fibers, andmixtures thereof. Preferred heat resistant polymeric fibers arepara-aramid fibers, and the preferred para-aramid fiber ispoly(paraphenylene terephthalamide fiber.

The at least one first yarn comprises at least 50 weight percentheat-resistant polymeric fiber based on the total weight of the firstyarn. In some embodiments, the at least one first yarn comprises atleast 60 weight percent heat-resistant polymeric fiber based on thetotal weight of the first yarn. In some embodiments, the at least onefirst yarn comprises 60 to 85 weight percent heat-resistant polymericfiber based on the total weight of the first yarn, and in some otherembodiments, the at least one first yarn comprises 60 to 80 weightpercent heat-resistant polymeric fiber, based on the total weight of thefirst yarn. In some embodiments, the at least one first yarn comprises100 weight percent heat-resistant polymeric fiber based on the totalweight of the first yarn.

At least 30 weight percent of the polymeric fiber present in the atleast one first yarn is cut-resistant heat-resistant polymeric fiberhaving a cut resistance of 500 grams force or higher per ASTM F2992-15.The cut performance of a fiber is determined by measuring the cutperformance of a 345 grams/square meter (10 ounces/square yard) fabricthat is woven or knitted from 100% of the fiber to be tested, and thenthe cut resistance (in grams-force) is measured by-ASTM F2992-15.

Cut-resistant heat-resistant polymeric fiber having a cut resistance of500 grams-force or higher per ASTM F2992-15 include para-aramid fibers,aramid copolymer fibers, polybenzazole fibers, polybenzimidazole fibersand mixtures thereof. Preferred cut-resistant heat-resistant polymericfibers are para-aramid fibers, and the preferred para-aramid fiber ispoly(paraphenylene terephthalamide fiber. The cut-resistantheat-resistant polymeric fiber in the at least one first yarn can be thesame or different from the heat-resistant polymeric fiber in the atleast one first yarn, if the heat-resistant polymeric fiber has adequatecut-resistance.

Therefore, it is understood that cut-resistant heat-resistant polymericfiber is both a heat-resistant polymeric fiber as previously defined anda cut-resistant fiber as previously defined. Further, the at least onefirst yarn can be 100% cut-resistant heat-resistant polymeric fiber.That is, it is understood that such a yarn having 100% cut-resistantheat-resistant polymeric fiber has therefore at least 50 weight percentheat-resistant polymeric fiber and also at least 30 weight percentcut-resistant heat resistant polymeric fiber. It is also understood thatthe at least one first yarn can include fiber that is heat-resistantpolymeric fiber as defined herein but is not cut-resistant fiber asdefined herein. Table 1 provides a guide, giving selected examplecompositions, as to the possible percentages of non-cut-resistantheat-resistant (Non-CR HR) polymeric fiber and cut-resistantheat-resistant (CH-HR) polymeric fiber.

TABLE 1 Total Total HR Minimum Maximum Maximum Minimum Non-HR Fiber inAmount of Amount of Amount of amount of Fiber in First Non-CR CR-HRNon-CR CR-HR First Yarn HR Fiber fiber HR fiber fiber Yarn (wt %) (wt %)(wt %) (wt %) (wt %) (wt %) 50 0 50 20 30 50 60 0 60 30 30 40 70 0 70 4030 30 80 0 80 50 30 20 90 0 90 60 30 10 100 0 100 70 30 0

Therefore, it is understood that the at least 30 weight percent of thepolymeric fiber present in the at least one first yarn is both acut-resistant and heat-resistant polymeric fiber as defined herein. Insome embodiments, the cut-resistant heat-resistant polymeric fiber ispresent in the at least one first yarn in an amount of 50 weight percentto 100 weight percent, based on the total amount of polymeric fiber inthe at least one first yarn. In some other embodiments, thecut-resistant heat-resistant polymeric fiber is present in the at leastone first yarn in an amount of 80 weight percent to 100 weight percent,based on the total amount of polymeric fiber in the at least one firstyarn. In other embodiments, the cut-resistant heat-resistant polymericfiber is present in the at least one first yarn in an amount of 80weight percent to 95 weight percent, based on the total amount ofpolymeric fiber in the at least one first yarn

In addition to the various example percentages of cut-resistantheat-resistant polymeric fiber and non-cut resistant heat-resistantpolymeric fiber shown in Table 1, in some embodiments, the at least onefirst yarn further comprises other synthetic or organic fibers orfilaments that are not heat-resistant polymeric fiber; that is, they donot meet the definition of a heat-resistant polymeric fiber providedherein. Essentially any type of fiber can be included as long as longthe final fabric meets the compositions described herein and theperformance criteria discussed herein. That is, the composition of theat least one first yarn comprises at least 50 weight percentheat-resistant polymeric fiber, based on the total weight of thepolymeric fiber in the first yarn, and wherein at least 30 weightpercent of the polymeric fiber is cut-resistant heat-resistant fiber;and the final fabric is a flame resistant fabric as defined herein andhas a maximum after-flame time of two seconds or less and weight loss of5 weight percent of less when tested per NFPA-2112-2018. Preferably, thefibers or filaments that are not heat-resistant polymeric fiber areorganic fibers and in some embodiments are polymeric organic fibers.Also, in some embodiments, if present, the fibers or filaments that arenot heat-resistant polymeric fiber are synthetic or organic staplefibers.

In some preferred embodiments, the at least one first yarn can furthercomprise flame-resistant fiber. By “flame-resistant fiber”, it is meantthat a fabric made solely from that fabric has a char length equal to orless than 4 inches and an afterflame equal to or less than 2 seconds perthe vertical flame test of ASTM D6143-99; but the fabric does not meetthe cut-resistance criteria previously described herein forcut-resistant heat-resistant polymeric fibers. Suitable flame-resistantfibers include meta-aramid fibers, with the preferred meta-aramid beingpoly(metaphenylene isophthalamide). Other potentially usefulflame-resistant fiber could include blends of meta-aramids andflame-retardant-treated (FR) cellulose, FR cotton, FR lyocell, ormixtures thereof. In some embodiments, the at least one first yarn has30 to 70 weight percent flame-resistant fiber, based on the total weightof the polymeric fiber in the first yarn. In some other preferredembodiments the at least one first yarn has 50 to 70 weight percentflame-resistant fiber, based on the total weight of the polymeric fiberin the first yarn.

Both the heat-resistant polymeric fiber and the cut-resistantheat-resistant polymeric fiber in the at least one first yarn are staplefibers preferably having a length of about 2 to 20 centimeters,preferably about 3.5 to 6 centimeters. Both the heat-resistant polymericfiber and the cut-resistant heat-resistant polymeric fiber in the atleast one first yarn are staple fibers preferably having a diameter of 5to 25 micrometers and a linear density of 0.5 to 7 dtex. Also, in someembodiments, if present, the fibers or filaments that are flameresistant fibers or are not heat-resistant polymeric fiber are staplefibers having dimensions similar to the above ranges for theheat-resistant polymeric fiber and the cut-resistant heat-resistantpolymeric fiber.

In some embodiments, the at least one first yarn comprising at least 50weight percent heat-resistant polymeric fiber, based on the total weightof the first yarn, and wherein at least 30 weight percent of thepolymeric fiber present in the at least one first yarn is cut-resistantheat-resistant polymeric fiber having a cut resistance of 500 gramsforce or higher per ASTM F2992-15, the at least one first yarn furtherhaving a sheath/core construction with the sheath comprising thecut-resistant heat-resistant polymeric fiber and the core comprising aninorganic fiber. When an application desires or requires superior cutresistance, at least one inorganic fiber is preferably added to theyarn. The sheath/core construction is used because the sheath staplefibers provide a cover and shield the inorganic filament in the corefrom direct abrasive contact with the skin giving the fabrics containingthe sheath/core yarn improved comfort.

In some embodiments when the inorganic fiber is present in the at leastone first yarn, the inorganic fiber is present in an amount of 15 to 40weight percent of the total weight of the first yarn. Likewise, themaximum amount of the heat-resistant polymeric fiber in thesesheath-core first yarns when the inorganic fiber is present is 85 weightpercent, based on the total weight of the first yarn. In some preferredembodiments, the sheath/core yarns have 60 to 80 weight percentheat-resistant polymeric fiber in the sheath and 20-40 weight percentorganic fiber in the core. Preferably the inorganic fiber in the core isa steel or tungsten. Preferably, the fiber in the core is present as oneor more continuous filaments.

The sheath fiber can be wrapped or spun around the inorganic filamentcore. Specifically, this can be achieved by known means, such as,conventional ring spinning including improvements to the conventionalprocess such as those utilizing COTSON technology; core-spun spinningsuch as DREF spinning; air-jet spinning using so-called core insertionwith Murata (now Muratec) jet-like spinning; open-end spinning, and thelike. Preferably the staple fiber is consolidated around the inorganicfilament core at a density sufficient to cover the core. The degree ofcoverage depends on the process used to spin the yarn; for example,core-spun spinning such as DREF spinning (disclosed, for example, inU.S. Pat. Nos. 4,107,909; 4,249,368; & 4,327,545) provides bettercoverage than ring spinning. Conventional ring spinning provides onlypartial coverage of the center core, but even partial coverage canprovide adequate sheath/core coverage. The sheath can also include somefibers of other materials to the extent that decreased cut resistance,due to that other material, can be tolerated

The incorporation of the at least one inorganic filament as the core inthis embodiment of the first yarn can be achieved, for example in itssimplest practical application, by passing a roving, sliver, orcollection of the heat-resistant and cut resistant fibers, andoptionally the non-heat resistant fibers through sets of drafting rollsto make a drafted fiber mass to be ring twisted into a single yarn. Theat least one inorganic filament is typically fed from a bobbin through aset of feed rolls and subsequently into the staple fibers prior to thefinal set of drafting rollers. Since the inorganic core filament(s) arenot elastomeric they do not have to be over-tensioned during insertioninto the yarn, with only enough tension applied to either the sheathfibers and the core as is conventionally used.

The at least one first yarn in the form of a sheath/core yarn generallycomprises 15-50 weight percent inorganic filament(s) with a total linearsheath/core yarn density of 100 to 5000 dtex. The core comprising aninorganic fiber can be a single filament, or may be multifilament, andis preferably a single metal filament or several metal filaments, asneeded or desired for a particular application or degree of cutprotection. By metal filament is meant filament or wire made from aductile metal such as stainless steel, copper, aluminum, bronze,tungsten and the like, or metal fiber constructions commonly known as“micro-steel”. Stainless steel is the preferred metal. The metalfilaments are generally continuous wires. Useful metal filaments are 1to 150 micrometers in diameter and are preferably 25 to 75 micrometersin diameter.

In some embodiments, the inorganic fiber is a glass filament. It can beone or more glass filaments, such as for example 110 dtex (100 denier)glass filament. However, glass is less preferred because it has less cutresistance per linear density than metal and it is much more criticalthat the glass be substantially covered by the staple fiber sheath tominimize skin irritation should the yarn be used in gloves, sleeves,etc., where the fabric is in contact with the skin. Therefore, in manyembodiments the inorganic fiber is a metal filament.

Again, it is understood that for these sheath/core yarns, thecut-resistant heat-resistant polymeric fiber is both a heat-resistantpolymeric fiber as previously defined and a cut-resistant fiber aspreviously defined. It is also understood that the at least one firstyarn can include fiber that is heat-resistant polymeric fiber as definedherein but is not cut-resistant fiber as defined herein. Table 2provides a guide, giving selected example compositions, as to thepossible percentages of total heat-resistant (CH-HR) polymeric fiber andtotal inorganic filament in the at least one first yarn, and furtherprovides possible percentages illustrating possible amounts ofnon-cut-resistant heat-resistant (Non-CR HR) polymeric fiber andcut-resistant heat-resistant (CH-HR) polymeric fiber.

TABLE 2 Total Total HR Fiber Minimum Maximum Maximum Minimum Inorganic(all types) Amount of Amount of Amount of Amount of Filament in FirstNon-CR CR-HR Non-CR CR-HR in First Yarn HR Fiber Fiber HR Fiber FiberYarn (wt %) (wt %) (wt %) (wt %) (wt %) (wt %) 50 0 50 20 30 50 60 0 6030 30 40 70 0 70 40 30 30 80 0 80 50 30 20 85 0 85 55 30 15

The at least one second yarn has a sheath/core construction with asheath of halogenated self-extinguishing staple fibers and a corecomprising at least one continuous elastomeric filament, wherein 60 to95 weight percent of the at least one second yarn is halogenatedself-extinguishing fiber, based on the total weight of the second yarn,and the halogenated self-extinguishing fiber is in contact with the atleast one continuous elastomeric filament, the second yarn being free orsubstantially free of inorganic fibers.

The at least one second yarn has a sheath/core construction, with thesheath of halogenated self-extinguishing staple fibers being in contactwith and covering the core of the at least one continuous elastomericfilament. It is believed that the halogenated self-extinguishing staplefibers provide an active flame-extinguishing cover for the core of theat least one continuous elastomeric filament. This is unlike coverfibers that provide “structural shielding” of the core, that is, coverfibers that simply char and remain in place when exposed to a flame andtherefore provide a structural barrier between a flame and the elasticcore. Instead, the sheath of halogenated self-extinguishing staplefibers decomposes in the presence of high thermal flux as in a flame,releasing a halogen gas that displaces localized oxygen from the yarnand hinders the burning of the core of the at least one continuouselastomeric filament. Therefore, it is believed that halogenatedself-extinguishing staple fibers should not only cover the core but bein direct contact with the core to locally displace oxygen from thesurface of the core of the at least one continuous elastomeric filament.

The sheath of halogenated self-extinguishing staple fibers can bewrapped or spun around the at least one continuous elastomeric filament.This can be achieved by known means, such as, conventional ring spinningincluding improvements to the conventional process such as thoseutilizing COTSON technology; core-spun spinning such as DREF spinning;air-jet spinning using so-called core insertion with Murata (nowMuratec) jet-like spinning; open-end spinning, and the like. Preferablythe staple fiber is consolidated around the core of at least onecontinuous elastomeric filament at a density sufficient to cover thecore. The degree of coverage depends on the process used to spin theyarn; for example, core-spun spinning such as DREF spinning (disclosed,for example, in U.S. Pat. Nos. 4,107,909; 4,249,368; & 4,327,545)provides better coverage than ring spinning. Conventional ring spinningprovides only partial coverage of the center core, but even partialcoverage is assumed a possible sheath/core structure herein.

It is believed the flame-extinguishing effect of the halogenatedself-extinguishing staple fibers is adequate when 60 to 95 weightpercent of the at least one second yarn is halogenatedself-extinguishing fiber, based on the total weight of the second yarn.In some embodiments, it is desirable for 80 to 95 weight percent of theat least one second yarn to be the halogenated self-extinguishing fiber,based on the total weight of the second yarn. The sheath can alsoinclude some fibers of other materials to the extent that decreasedflame-extinguishing effect, due to that other material, can be tolerated

Halogenated self-extinguishing fibers include those made fromhalogenated polymer. One especially preferred halogenatedself-extinguishing fiber is a fiber made from a modacrylic polymer. By“modacrylic polymer” it is meant preferably the polymer is a copolymercomprising 30 to 70 weight percent of acrylonitrile and 70 to 30 weightpercent of a halogen-containing vinyl monomer. The halogen-containingvinyl monomer is at least one monomer selected, for example, from vinylchloride, vinylidene chloride, vinyl bromide, vinylidene bromide, etc.

In some embodiments the modacrylic copolymers are those of acrylonitrilecombined with vinylidene chloride. In some embodiments, the modacryliccopolymer has in addition antimony oxide or antimony oxides. In somepreferred embodiments the modacrylic copolymer has either less than 1.5weight percent antimony oxide or antimony oxides, or the copolymer istotally free of antimony. Very low antimony content polymer andantimony-free polymer can be made by restricting the amount of, oreliminating entirely, any antimony compounds added to the copolymerduring manufacture. Representative processes for modacrylic polymers,including those that can be modified in this manner are disclosed inU.S. Pat. No. 3,193,602 having 2 weight percent antimony trioxide; U.S.Pat. No. 3,748,302 made with various antimony oxides that are present inan amount of at least 2 weight percent and preferably not greater than 8weight percent; and U.S. Pat. Nos. 5,208,105 & 5,506,042 having 8 to 40weight percent of an antimony compound. In some embodiments, themodacrylic polymer has an LOI of at least 26. In one preferredembodiment the modacrylic polymer has a LOI of at least 26 while alsobeing antimony-free.

The halogenated self-extinguishing staple fibers in the at least onesecond yarn are staple fibers preferably having a length of about 2 to 9centimeters, preferably about 3.5 to 6 centimeters. The halogenatedself-extinguishing staple fibers in the at least one second yarn arestaple fibers preferably having a diameter of 5 to 25 micrometers and alinear density of 0.5 to 7 dtex.

The fabric contains at least one second yarn having a sheath/coreconstruction with a sheath of halogenated self-extinguishing staplefibers and a core comprising at least one continuous elastomericfilament. The halogenated self-extinguishing fiber is in contact withthe at least one continuous elastomeric filament, eliminating the needfor the entire surface of the elastomeric filament(s) to actually befully covered by the staple fiber sheath.

In some embodiments, preferably at least 90% of the core is covered bythe sheath, as viewed under a microscope with the yarn in a relaxedcondition; that is, wherein the sheath-core yarn is viewed when notunder tension. The actual covering of the core can depend on the degreethe yarn is tensioned; however, it is believed the modacrylic providesits shielding benefit as long as it is in contact with the elastomericcore.

In some embodiments, 5 to 40 weight percent of the total weight of theat least one second yarn is the at least one continuous elastomericfilament. In some embodiments, a ring-spun second yarn has a corecomprising at least one elastomeric filament and a partially covering ofhalogenated self-extinguishing staple fibers. In some preferredembodiments, the core of elastomeric filament(s) comprises 5 to 25weight percent of the total sheath/core single yarn linear density of100 to 1500 dtex.

A “core comprising at least one continuous elastomeric filament”, asused herein, means a core formed from or containing filaments of anelastomer, the core preferably having the ability to return to itsoriginal length rapidly after repeated stretching, even to at leasttwice its original length. Preferred elastomeric cores includepolyurethane based yarns such as spandex or elastane; however, any fibergenerally having stretch and recovery can be used. Suitable well-knownelastomeric yarns also include the products sold under the tradenamesDorlastan® and Lycra®.

The preferred at least one continuous elastomeric filament is spandexfiber. As used herein, “spandex” has its usual definition, that is, amanufactured fiber in which the fiber-forming substance is a long chainsynthetic polymer composed of at least 85% by weight of a segmentedpolyurethane. Among the segmented polyurethanes of the spandex type arethose described in, for example, U.S. Pat. Nos. 2,929,801; 2,929,802;2,929,803; 2,929,804; 2,953,839; 2,957,852; 2,962,470; 2,999,839; and3,009,901.

In some processes for making spandex elastomeric filaments, coalescingjets are used to consolidate the spandex filaments immediately afterextrusion. It is also well known that dry-spun spandex filaments aretacky immediately after extrusion. The combination of bringing a groupof such tacky filaments together and using a coalescing jet will producea coalesced multifilament yarn, which is then typically coated with asilicone or other finish before winding to prevent sticking on thepackage. Such a coalesced grouping of filaments, which is actually anumber of tiny individual filaments adhering to one another along theirlength, is superior in many respects to a single filament of spandex ofthe same linear density.

The elastomeric filament in the elastomeric single yarn is preferably acontinuous filament and can be present in the second yarn in the form ofone or more individual filaments or one or more coalesced grouping offilaments. However, it is preferred to use only one coalesced groupingof filaments in the preferred elastomeric single yarn. Whether presentas one or more individual filaments or one or more coalesced groupingsof filaments, the overall linear density of the elastomer filament(s) inthe relaxed state is generally between 17 and 560 dtex (15 and 500denier) with the preferred linear density range being 44 to 220 dtex (40to 200 denier).

It is preferred to incorporate the at least one continuous elastomericfilament in the second yarn under tension by drawing or stretching theat least one continuous elastomeric filament prior to the combinationwith staple fibers by using a slower delivery speed of the at least onecontinuous elastomeric filament relative to the final second yarn speed.This drawing can be described as the stretch ratio of the continuouselastomeric filament, which is the final second yarn speed divided bythe delivery speed of the continuous elastomeric filament.

Typical stretch ratios are 1.5 to 5.0 with 1.5 to 3.50 being preferred.Low stretch ratios yield less elastic recovery while very high stretchratios make the single yarns difficult to process and the fabric tootight and uncomfortable. The optimum stretch ratio is also dependent onthe % weight content of elastomeric core. Tension devices can also beemployed to tension and stretch the elastomeric fiber but are lesspreferred due to the difficulty in reproducing and controlling tensionand stretch. The optimum stretch ratio is ultimately determined for eachfabric, based on the desired fit and feel of the fabric.

The incorporation of the at least one continuous elastomeric filamentinto the second yarn of halogenated self-extinguishing staple fibers canbe achieved, for example in its simplest practical application, bypassing a roving, sliver, or collection of the halogenatedself-extinguishing staple fibers through sets of drafting rolls to makea drafted fiber mass to be ring twisted into a single yarn. The at leastone continuous elastomeric filament is typically fed from a bobbinthrough a set of feed rolls and subsequently into the staple fibersprior to the final set of drafting rollers. The slower relative surfacespeed of the feed rollers to the surface speed of the drafting rollersis increased or decreased to determine the amount of elastic stretch andtension in the final ring-twisted single yarn using conventionaltechniques.

In some embodiments, the sheath of the at least one second yarn canfurther comprise heat-resistant polymeric fiber as previously describedherein. In some other embodiments, the sheath of the at least one secondyarn can further comprise cut-resistant heat-resistant polymeric fiberas previously described herein.

In some embodiments, the sheath of the at least one second yarn canfurther comprise flame-resistant fiber. By “flame-resistant” fiber, itis meant that a fabric made solely from that fabric has a char lengthequal to or less than 4 inches and an afterflame equal to or less than 2seconds per the vertical flame test of ASTM D6143-99. Suitableflame-resistant fibers include aramid fibers, with meta-aramid fibersbeing especially preferred; the preferred meta-aramid ispoly(metaphenylene isophthalamide). Potentially useful flame-resistantfiber include meta-aramid, polyamide-imide, flame-retardant-treated (FR)cellulose, FR cotton, FR lyocell, or mixtures thereof. In someembodiments, the at least one second yarn has preferably 5 weightpercent to as much as 35 weight percent flame-resistant fiber, based onthe total weight of the polymeric fiber in the at least one second yarn.Also, in some embodiments, the at least one first yarn has preferably 5weight percent to as much as 35 weight percent flame-resistant fiber,based on the total weight of the polymeric fiber in the at least onefirst yarn.

Any number of fibers can be included in the second yarn as long thesecond yarn and the final fabric meets the performance criteriadiscussed herein.

If used in the second yarn, the heat-resistant polymeric fiber, thecut-resistant heat-resistant polymeric fiber, or the flame-resistantfiber are preferably staple fibers preferably having a length of about 2to 20 centimeters, preferably about 3.5 to 6 centimeters. Also, if usedin the second yarn, the heat-resistant polymeric fiber, thecut-resistant heat-resistant polymeric fiber, and the flame-resistantfiber are preferably staple fibers preferably having a diameter of 5 to25 micrometers and a linear density of 0.5 to 7 dtex.

In some embodiments, the sheath of the at least one second yarn canfurther comprise what are known in the art as antistatic fibers orfibers that have the ability to reduce the accumulation of electricalcharge in the yarn or in the resultant fabric. In some preferredembodiments the sheath of the at least one second yarn includes at least1-5 weight percent antistatic fiber, based on the total weight the atleast one second yarn. Preferred antistatic fibers are those thatfunction by the present of carbon in the fiber, either as a carboncoating or carbon particles; especially antistatic fibers that help toeliminate the buildup of charge but are not considered to beelectrically conductive in a practical sense. In some embodiments,aramid fiber that contain carbon particles is preferred.

In preferred embodiments the second yarn is free or substantially freeof inorganic fibers. The cut-resistant benefits of any inorganic fibersis supplied by the first yarn, eliminating the need for additionalinorganic fiber in the second yarn for majority of the intendedapplications.

In some embodiments, a ply-twisted yarn is formed from the at leastfirst yarn and the at least second yarn. Ply-twisted yarns are made bytwisting together at least two individual single yarns. By the phrase“twisting together at least two individual single yarns”, it is meantthe two single yarns are twisted together without one yarn fullycovering the other. This distinguishes ply-twisted yarns from covered orwrapped yarns where a first single yarn is substantially or completelywrapped around a second single yarn so that ideally only the firstsingle yarn is exposed on the surface of the resulting covered yarn.

In one preferred embodiment, the ply-twisted yarn is made from at leasttwo singles yarns, the first singles yarns being (a) the at least onefirst yarn comprising at least 50 weight percent heat-resistantpolymeric fiber, based on the total weight of the first yarn, andwherein at least 30 weight percent of the polymeric fiber present in theat least one first yarn is cut-resistant heat-resistant polymeric fiberhaving a cut resistance of 500 grams force or higher per ASTM F2992-15,the at least one first yarn further having a sheath/core constructionwith the sheath comprising the cut-resistant heat-resistant polymericfiber and the core comprising an inorganic fiber; and the second singlesyarn being (b) the at least one second yarn having a sheath/coreconstruction with a sheath of halogenated self-extinguishing staplefibers and a core comprising at least one continuous elastomericfilament, wherein 60 to 95 weight percent of the at least one secondyarn is halogenated self-extinguishing fiber, based on the total weightof the second yarn, and the halogenated self-extinguishing fiber is incontact with the at least one continuous elastomeric filament, thesecond yarn being free or substantially free of inorganic fibers. Eachof the single yarns may have some twist.

In some embodiments, the ply-twisted yarns made from the two singlesyarns have a total linear density of from 200 to 3000 dtex. Theindividual staple fibers in either of the singles yarn can have a lineardensity of 0.5 to 7 dtex, with the preferred linear density range being1.5 to 3 dtex. The ply-twisted yarns, and the single yarns that make upthose ply-twisted yarns, can include other materials as long as thefunction or performance of the yarn or fabric made from that yarn is notcompromised for the desired use.

The ply-twisted yarns can be made from single yarns via the processesdisclosed in U.S. Pat. No. 6,952,915 to Prickett, and the ply-twistedyarns can have a wide range of ply twist disclosed therein.

The ply-twisted yarns may then be combined with other same or differentply-twisted yarns to form a yarn bundle to form a fabric, or theindividual ply-twisted yarns can be used to form the fabric, dependingon the desired fabric requirements. For example, two or more of thedescribed ply-twisted yarns can be combined to form a yarn bundle thatcan be fed to a knitting machine with or without twist. Alternatively, ayarn bundle could be made with one or more of the described ply-twistedyarns with one or more different single yarn to impart desiredproperties to the final fabric. Since modern knitting machines can knitfabric from a feed of multiple ply-twisted yarns, the bundle ofply-twisted yarns fed to the machine need not have twist, although twistcan be put into the bundle if desired.

The at least first yarn used in the preferred ply-twisted yarn whenthere is no inorganic core is preferably a single 420 dtex (380 denier,equivalent to 14 cotton count) yarn that is ring spun. The yarn has apoly(paraphenylene terephthalamide) (PPD-T) staple sheath, the PPD-Thaving a 3.8 cm (1.5 inch) cut length and a filament density of 1.7 dtexper filament (1.5 denier per filament).

The at least one second yarn used in the preferred ply-twisted yarn is asingle 330 dtex (295 denier, equivalent to 18 cotton count) yarn that isring-spun. The yarn has a modacrylic staple sheath that at leastpartially covers the elastomeric core filaments, the modacrylic staplehaving a 4.8 cm (1.89 inch) cut length and a filament density of 1.7dtex per filament (1.5 denier per filament). The elastomeric core is a78 dtex (70 denier) spandex coalesced filament yarn having a 3.0×stretch ratio (approximately 200 percent elongation). In some preferredembodiments, approximately 92 weight percent of the second yarn iscomprised of the modacrylic staple and with 8 weight percent of thesecond yarn being the elastomeric core.

The invention also relates to a cut-resistant woven or knitted fabricmade from yarns or a bundle of yarns comprising at least one first yarnand one second yarn. The invention further relates to a cut-resistantwoven or knitted fabric made from ply-twisted yarns or a bundle of yarnsthat includes a ply-twisted yarn, wherein the ply-twisted yarn comprisesat least one first yarn and one second yarn as described herein.

Specifically, the invention relates to a cut-resistant woven or knittedfabric made from a ply-twisted yarn made from at least two singlesyarns, the first singles yarn being (a) the at least one first yarncomprising at least 50 weight percent heat-resistant polymeric fiber,based on the total weight of the first yarn, and wherein at least 30weight percent of the polymeric fiber present in the at least one firstyarn is cut-resistant heat-resistant polymeric fiber having a cutresistance of 500 grams force or higher per ASTM F2992-15; and thesecond singles yarn being (b) the at least one second yarn having asheath/core construction with a sheath of halogenated self-extinguishingstaple fibers and a core comprising at least one continuous elastomericfilament, wherein 60 to 95 weight percent of the at least one secondyarn is halogenated self-extinguishing fiber, based on the total weightof the second yarn, and the halogenated self-extinguishing fiber is incontact with the at least one continuous elastomeric filament, thesecond yarn being free or substantially free of inorganic fibers; thefabric having a maximum after-flame time of two seconds or less andweight loss of 5 weight percent of less when tested per NFPA-2112-2018.

In some embodiments, the first singles yarn comprises an at least onefirst yarn further having a sheath/core construction with the sheathcomprising the cut-resistant heat-resistant polymeric fiber and the corecomprising an inorganic fiber.

The at least one first yarn and the at least one second yarn worksynergistically together in both the yarn and fabric. The at least onecontinuous elastomeric filament incorporated into the yarn(s) providesimproved stretch and recovery, while the heat-resistant staple fibersprovide structure in flame and the heat-resistant cut-resistant organicstaple fibers and inorganic filaments (if present) provide the yarn andfabric with excellent cut resistance. Fabrics made from such yarn(s) aresoft, comfortable and non-abrasive as well as cut resistant.

Ply-twisting of the first yarn with the second yarn is preferred becausethe ply-twisting helps hold the elastomer single yarn in an extendedstate without looping upon itself when relaxed. However, if thesheath/core elastomeric single yarn is co-fed with other single yarns ina bundle (without ply-twisting) to a knitting or weaving device withgood tension control, an acceptable fabric can be made. When the bundleis comprised of ply-twisted yarns tension control of the yarns whileknitting and weaving is less critical.

The preferred fabric is a knit fabric, and any appropriate knit patternis acceptable. Cut resistance and comfort are affected by tightness ofthe knit and that tightness can be adjusted to meet any specific need. Avery effective combination of cut resistance and comfort for many cutresistant articles has been found in, for example, single jersey andterry knit patterns. The fabrics have a basis weight of about 4 to 30oz/yd², preferably 6 to 25 oz/yd², the fabrics at the high end of thebasis weight range providing more thermal and cut protection.

Test Methods

Afterflame and Weight Loss were determined according to NFPA 2112-2018“Standard on Flame-Resistant Clothing for Protection of IndustrialPersonnel Against Short-Duration Thermal Exposures from Fire”,specifically the procedure outline in Section 8.8 of that Standard.

The determination of a “heat resistant polymeric fiber” as discussedherein can be achieved by the use of ASTM E2105-2016—Standard Practicefor General Techniques of Thermogravimetric Analysis (TGA) Coupled WithInfrared Analysis (TGA/IR). The analysis of whether or not a syntheticorganic polymer retains 90 percent of its original fiber weight isconducted by heating a sample in air to 500° C. at a rate of 20° C. perminute.

EXAMPLES

Knits Made from Ply-Twisted Yarn

Ply-twisted yarns and knits made from the yarns are exemplified inExamples 1, 2, and 3 and Comparative Example A and summarized in Table6.

Example 1

A ply-twisted elastic yarn was made by ply twisting a first yarn and asecond yarn.

The first yarn was a 14-cotton count sheath-core yarn having apara-aramid fiber sheath and a 50 micron stainless steel wire core, spunon a ring spinning frame. The para-aramid fiber was 2-inchpoly(paraphenylene terephthalamide) staple.

The second yarn was an 18-cotton count sheath-core yarn made bycore-spinning on a ring-spinning frame of 2-inch modacrylic staplearound a 70-denier spandex core; the spandex core was stretched 3× as itwas incorporated (spun) into the sheath-core yarn.

The resulting ply-twisted elastic yarn made by ply twisting the firstyarn and the second yarn had a total cotton count of 16/2, or 675denier. Relative amounts of the yarn components are shown in Table 3.

The resulting ply-twisted elastic yarn was knitted into a 13-gaugesleeve on a Shima-Seiki glove knitting machine. The resulting sleeve hadexcellent hand and form-fitting properties. A fabric sample fromresulting sleeve was flame tested in accordance with fire-resistantglove test method detailed in the NFPA-2112-2018 standard. The resultingstretch fabric was found to have 0-seconds of after-flame with 4.8% ofthe weight consumed during the tests, which was in below the 2-secondmaximum after-flame requirement and the 5% weight loss limit allowed inthe specification.

TABLE 3 Weight Percent of Weight Percent in Ply-twisted yarn SinglesYarn Component (%) (%) Para-aramid Fiber 36.4 65 Steel Wire 19.8 35Modacrylic Fiber 40.3 92 Elastic Fiber 3.5 8

Example 2

The ply-twisted elastic yarn of Example 1 was repeated, with thefollowing exceptions.

The first yarn was a 26-cotton count yarn having a para-aramid fibersheath and a stainless steel wire core made with a 35 micron stainlesssteel wire core. The second yarn was a 32-cotton count yarn having amodacrylic sheath and a 40-denier spandex core that was stretched 3×during spinning.

As in Example 1, the resulting ply-twisted elastic yarn made by plytwisting the first yarn and the second yarn had a total cotton count of29/2, or 371 denier. Relative amounts of the yarn components are shownin Table 4.

The resulting ply-twisted elastic yarn was knitted into an 18-gaugesleeve on a Shima-Seiki glove knitting machine. The resulting sleeve hadexcellent form-fitting properties. A fabric sample from the resultingsleeve was washed to remove knitting oils and finishes and flame testedin accordance with fire-resistant glove test method detailed in theNFPA-2112-2018 standard. The resulting stretch fabric was found to have0 seconds of after-flame with 3.3% of the weight consumed during thetests, which was in below the 2-second maximum after-flame requirementand the 5% weight loss limit allowed in the specification.

TABLE 4 Weight Percent of Weight Percent in Ply-twisted yarn SinglesYarn Component (%) (%) Para-aramid Fiber 37.4 68 Steel Wire 17.8 32Modacrylic Fiber 41.2 92 Elastic Fiber 3.6 8

Example 3

The ply-twisted elastic yarn of Example 1 was repeated, with thefollowing exceptions.

The first yarn was a 19.5-cotton count yarn having a para-aramid fibersheath and a stainless steel wire core made with a 45 micron stainlesssteel wire core that was stretched 3× during spinning. The second yarnwas a 32-cotton count sheath-core yarn having a 40-denier spandex core;however, the sheath was a blend of 82 weight % modacrylic staple fiberand 10 weight percent of a 2-inch cut-length meta-aramid staple fiberblend; specifically, the meta-aramid blend contained 93 weight %poly(metaphenylene isophthalamide) staple fiber, 5 weight %poly(paraphenylene terephthalamide) staple, and 2 weight % carbon-corenylon antistatic fiber.

As in Example 1, the resulting ply-twisted elastic yarn made by plytwisting the first yarn and the second yarn had a total cotton count of24/2, or 439 denier. Relative amounts of the yarn components are shownin Table 5.

The resulting ply-twisted elastic yarn was knitted into an 18-gaugesleeve on a

Shima-Seiki glove knitting machine. The resulting sleeve had excellentform-fitting properties.

A fabric sample of the sleeve that was produced was washed to removeknitting oils and finishes and then flame tested in accordance withfire-resistant glove test method detailed in the NFPA-2112-2018standard. The resulting stretch fabric was found to have 0-seconds ofafter-flame with 3.9% of the weight consumed during the tests, which wasin below the 2-second maximum after-flame requirement and the 5% weightloss limit allowed in the specification.

Another fabric sample of the sleeve that was produced was flame testedin accordance with fire-resistant glove test method detailed in theEN407:2020 standard. The resulting stretch fabric was found to have0-seconds of after-flame and 0-seconds of after-glow after 3 seconds and15 seconds of exposure to the flame, which was in below the 2-secondmaximum after-flame and 5-second maximum after-glow requirement toachieve the highest ranking described in the specification.

TABLE 5 Weight Percent of Weight Percent in Ply-twisted yarn SinglesYarn Component (%) (%) Para-Aramid Fiber 37.3 60 Steel Wire 24.9 40Modacrylic Fiber 31.0 82 Meta-Aramid Fiber* 3.8 10 Elastic Fiber 3.0 8*Actual blend of 93 wt % meta-aramid fiber, 5 wt % para-aramid fiber,and 2 wt % carbon-core nylon antistatic fiber.

Comparative Example A

A comparative ply-twisted elastic yarn similar to that of Example 3 wasmade; however, the first yarn having a para-aramid fiber sheath and astainless steel wire core was made with 1.5-inch poly(paraphenyleneterephthalamide) staple and a 45-micron stainless steel wire core. Thesecond yarn, which was again a 32-cotton count sheath-core yarn, had asheath of solely 1.5 inch cut-length nylon staple core-spun around the40-denier spandex core.

The resulting 24's-2 count ply-twisted yarn was knitted into an 18-gaugesleeve on a Shima-Seiki glove knitting machine. The resulting sleeve hadexcellent form fitting properties.

However, the sample produced was flame tested in accordance withfire-resistant glove test method detailed in the EN407:2020 standard.The resulting stretch fabric was found to have at least 25-seconds ofafter-flame after 3 seconds of exposure to the flame, which was higherthan 20-second maximum after-flame requirement to achieve even thelowest ranking described in the specification.

Because of the excessive afterflame with only 3-seconds of flameexposure, subsequent testing was not done for 15-second exposure in theEN407 test nor the 12-second exposure in the NFPA-2112 test.

TABLE 6 After Weight Yarn Knit First Second Flame Loss Ex. Type TypeYarn Yarn (sec) % 1 One 13 Para-Aramid Modacrylic 2 4.8 Ply- GaugeSheath/ Sheath/ Twisted Knit Steel Core Spandex Core Yarn 2 One 18Para-Aramid Modacrylic 0 3.3 Ply- Gauge Sheath/ Sheath/ Twisted KnitSteel Core Spandex Core Yarn 3 One 18 Para-Aramid Modacrylic + 0 3.9Ply- Gauge Sheath/ Meta-Aramid Twisted Knit Steel Core Sheath/ YarnSpandex Core A One 18 Para-Aramid Nylon Sheath/ >25 NA Ply- GaugeSheath/ Spandex Core Twisted Knit Steel Core Yarn

Knits Made by Co-Knitting Two Parallel Ends

Knits made from co-knitting the yarns by supplying individual ends or abundle of individual end to knitting machine are exemplified in Example4 and Comparative Examples B and summarized in Table 4.

Example 4

A first end that is a 2-ply para-aramid ring spun yarn, each ply yarnmade from 2-inch poly(paraphenylene terephthalamide) staple yarns, witheach of the 2 ply yarns having a 16 cotton count; was co-knitted with asecond end that was the 18 cotton count sheath-core yarn of Example 1.

The two ends were then co-knit two-ends in into a sleeve on a 13-gaugeknitting machine. The resulting sleeve had excellent hand and formfitting properties.

A fabric sample of the produced sleeve was washed to remove knittingoils and finishes and flame tested in accordance with fire-resistantglove test method detailed in the NFPA-2112-2018 standard. The resultingstretch fabric was found to have 0-seconds of after-flame with 2.5% ofthe weight consumed during the tests, which was in below the 2-secondmaximum after-flame requirement and the 5% weight loss limit allowed inthe specification.

Comparative Example B

An end of 12 cotton count modacrylic ring spun yarn, made from 2-inchmodacrylic staple, was co-knitted with an end of 18 cotton countsheath-core yarn of Example 1. The two ends were co-knitted two-ends ininto a sleeve on a 13-gauge knitting machine. The resulting sleeve hadexcellent hand and form fitting properties.

The sample produced was washed to remove knitting oils and finishes andflame tested in accordance with fire-resistant glove test methoddetailed in the NFPA-2112-2018 standard. The resulting stretch fabricwas found to have 2.3-seconds of after-flame with 5.8% of the weightconsumed during the tests, which was above the 2-second maximumafter-flame requirement and the 5% weight loss limit allowed in thespecification.

TABLE 7 After Weight Yarn Knit First Second Flame Loss Ex. Type TypeYarn Yarn (sec) % 4 One 13 Para-Aramid Modacrylic 0 4.8 Ply- GaugeSingles Yarn Sheath/ Twisted Knit Plied with Spandex Core YarnPara-Aramid Singles Yarn B One 13 Modacrylic Modacrylic 2.3 5.8 Ply-Gauge Singles Yarn Sheath/ Twisted Knit Spandex Core YarnKnits Made from Weft-Insertion

Knits made from co-knitting the yarns via weft-insertion are exemplifiedin Example 3 and Comparative Examples B & C and summarized in Table 4.

Example 5

A first end, that is a 2-ply para-aramid ring spun yarn, each ply yarnmade from 2-inch poly(paraphenylene terephthalamide) staple yarns, witheach of the two ply yarns having a 16 yarn count, was co-knitted with asecond end that was a modacrylic sheath-spandex core elastic yarn, madeby ring-spinning a 1200 denier core-spun fiber, with a 440 denierspandex core, that was stretched 3× during the yarn spinning process, toproduce a fire-resistant yarn. The composition of the elastic core yarnwas approximately 12% spandex and 88% modacrylic staple fiber.

The first and second ends were co-knitted into a 13-gauge knitted sleevecuff on a Shima-Seiki flatbed knitted machine, using a weft insertiontechnique that inserted in every third stitch the modacrylicsheath-spandex core elastic yarn. The resulting sleeve had excellentform fitting properties.

The sample produced was washed to remove knitting oils and finishes andflame tested in accordance with fire-resistant glove test methoddetailed in the NFPA-2112-2018 standard. The resulting stretch fabricwas found to have 0-seconds of after-flame with 4% of the weightconsumed during the tests, which was in below the 2-second maximumafter-flame requirement and the 5% weight loss limit allowed in thespecification.

Comparative Example C

The 2-ply para-aramid ring spun yarn first end of Example 5 was combinedwas a different second end, that second end being a polyester fiberwrapped-covered rubber elastic cord from Supreme Elastic Corporation,and the first and second ends were co-knitted to produce an elastic cuffon a Shima-Seiki flatbed knitted machine. The elastic cord compositionwas estimated to be 75% polyester fiber and 25% rubber. The ends wereco-knitted using a weft insertion technique that inserted the polyesterfiber wrapped-covered rubber elastic cord in every third stitch of the13-gauge knitted sleeve. The resulting sleeve had excellent form-fittingproperties.

A fabric sample from the produced sleeve was washed to remove knittingoils and finishes and flame tested in accordance with fire-resistantglove test method detailed in the NFPA-2112-2018 standard. The resultingfabric was found to have 43-seconds of after-flame with 9% of the weightconsumed during the tests, which was in excess of the 2-second maximumafter-flame and 5% weight loss limit allowed in the specification.

Comparative Example D

4-ends of a ring spun yarn, made from 2-inch modacrylic staple, witheach yarn having a 35 cotton count, was co-knitted with a sheath-coreelastic yarn having a modacrylic sheath and spandex core. Thesheath-core elastic yarn was made by ring-spinning a 1200 deniermodacrylic staple yarn with a 440 denier spandex core, while the spandexwas stretched 3× during spinning to produce the sheath-core elastic yarnhaving a composition that was approximately 12% spandex and 88%modacrylic staple fiber. The elastic yarn was co-knitted using a weftinsertion technique in every third stitch of the 13-gauge knitted sleevebeing knitted on the glove knitting machine. The resulting sleeve hadexcellent form fitting properties.

A fabric sample from the produced sleeve was washed to remove knittingoils and finishes and flame tested in accordance with fire-resistantglove test method detailed in the NFPA-2112-2018 standard. The resultingstretch fabric was found to have 0-seconds of after-flame with 10% ofthe weight consumed during the tests, which was in below the 2-secondmaximum after-flame requirement but above the 5% weight loss limitallowed in the specification.

TABLE 8 After Weight Yarn Knit First Second Flame Loss Ex. Type TypeYarn Yarn (sec) % 5 Two 13 Gauge Ply-Twisted Modacrylic 0 4 Ends Co-KnitPara-Aramid/ Sheath/ using weft Para-Aramid Spandex insertion Core C Two13 Gauge Ply-Twisted Polyester 43 9 Ends Co-Knit Para-Aramid/ Sheath/using weft Para-Aramid Rubber insertion Core D Four 13 Gauge SeparateModacrylic 0 10 Ends Co-Knit Modacrylic Sheath/ using weft Yarns Spandexinsertion Core

1. A flame-resistant cut-resistant fabric, comprising: (a) at least onefirst yarn comprising at least 50 weight percent heat-resistantpolymeric fiber, based on the total weight of the polymeric fiber in thefirst yarn, wherein at least 30 weight percent of the polymeric fiberpresent in the at least one first yarn is cut-resistant heat-resistantpolymeric fiber having a cut resistance of 500 grams force or higher perASTM F2992-15; and (b) at least one second yarn having a sheath/coreconstruction with a sheath of halogenated self-extinguishing staplefibers and a core comprising at least one continuous elastomericfilament, wherein 60 to 95 weight percent of the at least one secondyarn is halogenated self-extinguishing fiber, based on the total weightof the second yarn, and the halogenated self-extinguishing fiber is incontact with the at least one continuous elastomeric filament, thesecond yarn being free or substantially free of inorganic fibers;wherein the fabric has a maximum after-flame time of two seconds or lessand weight loss of 5 weight percent of less when tested perNFPA-2112-2018.
 2. The fabric of claim 1, wherein the at least one firstyarn has a sheath/core construction with a sheath comprising thecut-resistant heat-resistant polymeric fiber and a core comprising aninorganic fiber.
 3. The fabric of claim 1, wherein the heat-resistantpolymeric fiber or the cut-resistant heat-resistant polymeric fiber isaramid copolymer, para-aramid, polybenzazole, polybenzimidazole,polyimide or mixtures thereof.
 4. The fabric of claim 3 wherein theheat-resistant polymeric fiber or the cut-resistant heat-resistantpolymeric fiber is para-aramid.
 5. The fabric of claim 3, wherein thepara-aramid fiber is poly(paraphenylene terephthalamide.
 6. The fabricof claim 1, wherein the at least one first yarn further comprises aflame resistant fiber that is not cut-resistant.
 7. The fabric of claim6, wherein the flame resistant fiber is meta-aramid, polyamide-imide,flame-retardant-treated (FR) cellulose, FR cotton, FR lyocell, ormixtures thereof.
 8. The fabric of claim 7, wherein the flame resistantfiber is meta-aramid.
 9. The fabric of claim 8, wherein the meta-aramidis poly(metaphenylene isophthalamide).
 10. The fabric of claim 1,wherein 80 to 95 weight percent of the total weight of the at least onesecond yarn is the halogenated self-extinguishing fiber.
 11. The fabricof claim 1, wherein the halogenated self-extinguishing fiber ismodacrylic fiber.
 12. The fabric of claim 1, wherein 5 to 40 weightpercent of the total weight of the at least one second yarn is the atleast one continuous elastomeric filament.
 13. The fabric of claim 1,wherein the at least one continuous elastomeric filament is spandexfilament.
 14. The fabric of claim 1, wherein the inorganic fiber ismetal filament.
 15. The fabric of claim 1, wherein the inorganic fiberis glass filament.
 16. The fabric of claim 1, wherein the sheath of theat least one second yarn further comprises heat-resistant polymericfiber.
 17. The fabric of claim 1, wherein the sheath of the at least onesecond yarn further comprises a flame resistant fiber that is notcut-resistant.
 18. The fabric of claim 17, wherein the flame resistantfiber is meta-aramid, polyamide-imide, flame-retardant-treated (FR)cellulose, FR cotton, FR lyocell, or mixtures thereof.
 19. The fabric ofclaim 18, wherein the flame resistant fiber is meta-aramid.
 20. Thefabric of claim 19, wherein the meta-aramid is poly(metaphenyleneisophthalamide).
 21. The fabric of claim 1, wherein the sheath of the atleast one second yarn further comprises an antistatic fiber.
 22. Thefabric of claim 1, comprising a ply-twisted yarn of the at least onefirst yarn and the at least one second yarn.
 23. The fabric of claim 1,wherein the fabric is a knit fabric.
 24. The fabric of claim 1, havingco-knit structure of the at least one first yarn and the at least onesecond yarn.
 25. The fabric of claim 24 wherein the at least one firstyarn and the at least one second yarn are in a parallel relationship toone another in the co-knit structure.
 26. The fabric of claim 24 whereinthe at least one second yarn is a weft insertion in the co-knitstructure.
 27. A glove or other article comprising the fabric of claim1.